Kaushik et al (28) carried out a small trial to determine if microneedles are perceived as painless by human subjects. Microneedle arrays of 150ï¿½m length, were inserted into the skin of 12 subjects and compared to pressing a flat surface against the skin (negative control) and inserting a 26-gauge hypodermic needle into the skin surface (positive control). Subjects were unable to distinguish between the painless sensation of the flat surface and that caused by microneedles. Kaushik S, Hord AH, Denson DD, McAllister DV, Smitra S, Allen MG, Prausnitz MR. Lack of pain associated with microfabricatedmicroneedles. Anesth Analg. 2001 Feb;92(2):502-4.

Fernandes D. demonstrated that microneedling can induce up to a 1,000% increase in collagen after a single treatment. Fernandes D. Minimally invasive percutaneous collagen induction. Oral Maxillofac Surg Clin North Am 2006;17:51-63.